Introduction: Mineral and bone disorders are common in patients with chronic kidney disease (CKD). Vitamin D plays an important role in calcium-phosphorus balance.

Objectives: The main aim of this investigation is to assess the relation between circulating levels of 25(OH) vitamin D and parathyroid hormone (PTH) and estimating the best threshold of vitamin D which may prevent secondary hyperparathyroidism.

Patients and Methods: This cross-sectional study was conducted between January 2014 to September 2015. Adult patients with CKD who were not on routine peritoneal dialysis or hemodialysis and did not receive any kidney transplantation, enrolled to this study. Patients who were pregnant or who were on vitamin D supplementation therapy were excluded. Basic demographic and laboratory information were measured.

Conclusion: This study again confirms this fact that sufficient level of serum 25(OH) vitamin D is mandatory in patients with CKD in order to prevent secondary hyperparathyroidism. Although this study recommends level of serum 25(OH) vitamin D to be above 13 ng/mL for this purpose.